A multicolor display is employed as a display for a liquid crystal color television and the like. It generally is composed of a transparent substrate and a color layer thereon. Recently, in a process for producing a multicolor display, electrodeposition has become noteworthy.
Japanese Kokai Publication (unexamined) No. 114572/1984 discloses a process for producing a multicolor display wherein, as shown in FIG. 3, a transparent electrode 2 is patterned on a glass substrate 4 (see FIG. 3(a)) which is then immersed in an electrodeposition bath while a voltage is applied to a portion of the transparent electrode 2 to be colored with, for example, red to form a red color layer 3 (see FIG. 3(b)), then green and blue color layers 3 were formed on each portion of the electrode 2 by passing electricity (see FIG. 3(c) and (d)). In the apparatus produced by the process mentioned above, the transparent electrode is employed not only for electrodepositing a color layer, but also for driving liquid crystal. However, since the color layer electrodeposited on the electrode is insulating, a high driving voltage for liquid crystal is needed. In order to reduce the driving voltage, an additional transparent layer which is for driving liquid crystal is formed on the color layer (see FIG. 3(e)). The formation of the additional electrode is time and cost consuming because it makes the process complicated and requires a further patterning process. Also, since transparent electrode generally has a light transmittance of 80 to 85%, two transparent electrodes reduces the light transmittance of the display, thus deteriorating the properties of the multicolor display.
Another process which does not employ electrodeposition has also been proposed, which includes screen printing, photolithography and the like. Screen printing has a limit in the miniaturization of the pattern and in the accuracy of printing which results in a decline in the discrepancy of the pattern. Photolithography makes possible miniaturization of the pattern, but protection against dyeing is necessary in order to avoid double dyeing. It makes the process complicated.